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JIC Setup help - super bouncy on street

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Old 09-08-2007, 01:25 PM
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FotoVeloce
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Default JIC Setup help - super bouncy on street

I've been trying to get this worked out for a little while now. Run the forum searches, looked for options like lighter springs, even went as far as talking to JIC in SoCal for nearly an hour.

I think I set up the initial heights on the JIC wrong, or maybe I have the shock adjusters are the wrong ends of the adjustment?

PROBLEM:
On the street, the car bounces, badly. It's like I took out the stock springs, but them and put them back in with the stock shocks. It's rights like a poorly done ricer-mobile and this simply will NOT do for my Pcar.

When I got my JIC's the adjusters for the front were missing (I did not know that before I installed them). I have them now but no idea how to install them with the shocks in the car, so they were at some factory set compression/rebound setting unknown to me.

The rears I set at 4 off full soft.

When I set the car in a corner on the street, on an imperfect road (does not have to be rough at all) it occilates to the point of being downright scary. On the local surface streets it just bounces and bounces and sometimes developes a sort of 'standing wave characteristic' until the pavement changes again.

What I am wondering is this:

- when installed did I not leave enough throw in the shock when the car is on the ground? ie. did I run the collars too far down the body when setting height - and run the lower adjusters down as well to compensate, putting the shock pistons way out the range they are optimal for?

- are my springs too stiff for street use? 7kg / 11kg. I spoke with JIC and they said 6/10 would the lightest they would go or the car could bottom out.

- maybe I have the shocks set way to soft, thus the springs are over-powering the shock action giving it the cheap-o lowering job feel?

I'd love to have another 993 driver, especaially one with JIC's give the car a drive and tell me if it's jacked up or just how it will work on the street.

Suggestions on how/where to start diagnosing the problem are welcomed.

HELP!
Old 09-08-2007, 01:28 PM
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jdistefa
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I think Bill Verburg has these on his RS clone - you should PM him.
Old 09-08-2007, 03:06 PM
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rcwelch
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Sorry to hear about your problem...it sounds like something to do with the initial adjusters being missing. I can't help as I have pss-9's, but I will say that the adjustable shocks/coil over springs really work well on the 993. Good luck, but I wouldn't be to fast to give them up for something else. It may require taking them out and starting again.
Old 09-08-2007, 04:55 PM
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Don Plumley
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I'm running JIC's with 7/10 - bouncy is not a problem I have - even with full soft.

Can you take pics to see how they look?

Here's how the adjusters fit in the front shocks:



Turn right hand 15 clicks for full hard.

What kind of sways are you running?
Old 09-08-2007, 05:20 PM
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Bill Verburg
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JIC 7& 10 is still ~2x the rate of RoW M030,

I run 7&10 too. The ride is abrupt because of the damping, turn to full soft to reduce it.
Old 09-08-2007, 07:56 PM
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David 23
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Post a photo of how yours is installed, perhaps those of us with JIC can compare and find the problem. Your car should NOT be bouncy as you describe, regardless of your shocks set to hard or soft. JIC systems, when properly installed are taut and controlled.
Old 09-09-2007, 11:59 AM
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FotoVeloce
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That's what I thought. It should not be bouncing like that. I drove the car 250 miles last night to a wedding. At speed, it's nice and controlled but below 50 or so it's a bouncefest.

After thinking about it on the way home last night, I plan to pull the fronts and install the adjusters and try to get that right. Also thinking of running up the upper collars to place the 'average piston position' (for lack of the technical term I don't know) higher in the body, and see how that goes.

Tight I can deal with, the bouncy is just.. wicked un-nerving. I wondering if there is a massive imbalance in the corner balancing that could be initiating this?

What I noticed last night was the detents for the front adjusters is in the adjuster itself, not the shock body! I thought it odd that when I inserted a 2mm Allen into the base of the body and turned it towards full soft I did not feel any detents. Now I know why. This also made me think that the shocks right-left are possibly way out of sync with each other.

Sounds like I really hosed myself up with the install. I'm wondering how to get the fronts back to the right starting point to install the adjusters.
Old 09-09-2007, 04:32 PM
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David 23
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Stick with it and get it straight. Once you have it installed correctly and adjusted, I think you will be very happy with the system. I am still very impressed with the system after having it on for a couple years now, with lots of hard track (like this morning!).
Old 09-09-2007, 04:41 PM
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FotoVeloce
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Back on the jackstands she goes tonight. This will keep me out of the strip clubs for a few nights.
Old 09-23-2007, 10:02 PM
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FotoVeloce
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OK. Finally had a couple of hours to R&R the JIC's on the front and install the little adjusters. What I didn't know until recently is that that those detents are in the adjuster itself, not the shock.

So.. to install them, I ran the adjuster set 'screw/allen' all the way in to soft. Then installed the adjusters, tiny dab of Locktite blue and tightened them up.

Turned them out to S+5 and re-installed the shocks.

I only have to put the wheels back on and test. The rear remote adjusters for the back are STILL on order from JIC. I wonder if the local shop that ordered them about 3 weeks ago just tossed them on the sock shelf or the got installed on another 993 (but that's another problem).

Here is the photo. I don't know if the angle is useful or not, but est I could get with the full shock in view. Also a picture of the PN and ratings, including the rate of the helpers if there is any info to be had there.
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Old 09-23-2007, 10:25 PM
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allill
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Those JIC's sure are purddy.
Old 09-26-2007, 01:23 PM
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FotoVeloce
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After setting the fronts to 5 it seems a lot less bouncy. Which make logical sense if the shocks where not turned up hight enough to control the springs. It seems to feel better. I'm still waiting on my rear remote adjusters then I'll turn up the rear and maybe.. all this will be worked out.

I still have some wandering issues that might be worn suspension or possibly a really screwed up Kinnematic toe setting in the rear.
Old 09-26-2007, 04:19 PM
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JPS
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Do you have to jack the car to adjust (get the load off them), or can you do it with the car sitting flat?
Old 09-26-2007, 04:46 PM
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FotoVeloce
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I jack it up to do it because I remove the wheels or access. I have not tried to do it on a lift. There is not a whole lot of room in there even jacked up and the wheels off so.. not sure if it's even possible to do it in the loaded position.
Old 09-26-2007, 05:09 PM
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I've had issues with the JICs (mostly install) but not the ride. It rides more comfortable on the street and better on the track at the same time if thats possible. Mine are on the 964 btw.
YGM.


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